Water level has been lowered, there shouldn't be any issues with ducks killing themselves or small units refusing to fire in the shallows.
The zk-dependent metal patches have been replaced by raaar's new metal system, offering greater performance, flexibility, and better compatibility with terraforming.

Maps are easy to make, and hard to make well.

See the springRTS mapping wiki for technical documentation and a general overview of all the parts of a map. https://springrts.com/wiki/Mapdev:Main

But understand this was the old way of doing things, and new tools offered by Zero-K like lua metalconfigs and polygonal startboxes make parts of this obsolete. Springboard is now available allowing mapmaking inside engine, and is also the best way to place features (this is how features were done on this map.)

See more about Springboard here: https://github.com/Spring-SpringBoard/SpringBoard-Core

I think the map would benefit from much less metal reclaim in the sea (ferns are ok) since otherwise amph is mandatory. Some of that metal could end up on land instead, to keep the map's uniqueness of large reclaim.

I disagree.

Like 60% of the metal reclaim is land accessible, that last 40% doesn't really matter because of how long it would take to completely reclaim everything.